The proposed research would continue the development of a piezoelectric immunosensor potentially useful for the diagnosis of tuberculosis (TB) and other mycobacterial infections. Tuberculosis has been declared a global public health emergency, and is a common and serious opportunistic infection in patients with AIDS. The feasibility of detecting mycobacterial antigens in both liquid and vapor phases has been demonstrated with a prototype piezoelectric immunosensor. Vapor phase detection suggests that detection of mycobacterial antigens in expired breath may permit rapid, on-site screening of high risk populations for pulmonary TB. Liquid phase detection will permit rapid diagnosis of mycobacterial infections from clinical specimens such as sputum, saliva, bronchoalveolar lavage fluids, serum, synovial fluid and cerebrospinal fluid. Research will now proceed to antigen detection in actual clinical samples, improvements in sensitivity, further device development, and preliminary clinical testing. The long-term objective of the work is to develop clinically valuable, commercially viable biosensors for screening and diagnosis of mycobacterial infections, including TB. PROPOSED COMMERCIAL APPLICATION: Tuberculosis remains an extremely serious health problem in many parts of the world, and its resurgence in this country lends additional impetus to efforts to develop a rapid method of diagnosis. The piezoelectric immunosensor developed in Phase I represents an entirely novel technological approach to this problem, with potential advantages over existing technology. Piezoelectric biosensors offer great sensitivity, rapidity of response, and portability for field use. S&P Medical expects to patent major features of the prototype, and has interested a larger corporation in jointly pursuing the final commercialization of the devices resulting from this research.